1. Field of the Invention
Applicant's invention relates to a process for making block polymers or copolymers from isotactic polypropylene.
2. Background Information
The manufacture of polypropylene and polyethylene has evolved to the point of generating high quantities of specific commodity polymers. Although these polymers have great potential for their specific uses, they are limited in scope for conversion to polymer types with other properties. It is the purpose of the present application to disclose a unique approach to using these polymers, either virgin or recycled, as the building blocks for novel polymers with other properties. These novel polymers can be considered block polymers that contain segments for reactive functionality. This becomes especially important in the recycling efforts for the commodity polyolefin polymers and provides an outlet for the large amount of available recycled material. The method disclosed herein provides a method for obtaining novel block polymers with a wide range of properties such as decreased viscosity, improved flexibility, improved hydrophilic character, and higher molecular weights. In addition this method allows more use of the reactive capabilities of modern extruders. Additionally in this process these polymers can be blended with other polymers to provide compatible exudates. Alone or blended together with other polymers these novel polymers can be used in the production of articles such as fibers, extruded sheets, films, adhesive products, molded products, or other similar articles.
Amorphous or non-crystalline polymers are used extensively for paper, film, and foil laminations and as ingredients for adhesives, sealants, and hot melt formulations. These non-crystalline polymers are chosen and used for the properties of adhesion, flexibility, surface tack, and overall compatibility with the systems in which they are used. In the past amorphous polypropylene was introduced in the adhesive market because it was a by-product of isotactic polypropylene synthesis. With current processing and advances in catalyst technology, the availability of amorphous polypropylene as a byproduct has been virtually eliminated. For their properties, especially strength, other amorphous polymers are commonly used. These include polyethylene, butyl elastomers, and cross linked butyl rubber, styrenic block copolymers (SBC) such as styrene butadiene (SBR) or styrene-ethylene butadiene styrene rubber, ethylene or similar copolymers of vinyl acetates, acrylates, such as methyl methyacrylate, or butylacrylate copolymers, polyisobutylene elastomers or the like.